Cyan lights to mark robotaxis

Federal regulators have finally picked a color for the lights that will tell the world when a car is driving itself: cyan. The National Highway Traffic Safety Administration released proposed changes to Federal Motor Vehicle Safety Standard No. 108 to establish this distinct blue-green hue as a national signal for automated driving systems.

The agency is rewriting the rules to accommodate vehicles without human drivers. The proposal aims to cut red tape for new car designs while creating a uniform way for robotaxis to communicate with the people around them. This move ends years of industry debate over how to visually distinguish self-driving cars from traditional ones.

NHTSA is specifically proposing cyan-colored marker lamps. The goal is to provide a clear and consistent signal to law enforcement and other road users whenever an automated system is in control. Regulators believe this specific shade fills a visual gap in current automotive lighting conventions.

The choice of cyan is driven by practical necessity. The auto industry already uses red, amber, and white lights for functions like brakes, turn signals, and headlights. Flashing blue and red lights are reserved for emergency vehicles. By introducing a new color, the agency hopes to avoid confusing drivers who might mistake a robotaxi for a police car or a car with a malfunction.

There is some precedent for this approach. Mercedes-Benz previously received state-level approval to use turquoise lights on its Level 3 Drive Pilot cars. Although the automaker later scrapped that specific plan in favor of a Level 2++ system, the concept of using a unique light color has been tested in the market.

The proposed rule would make these cyan marker lights optional for manufacturers. However, if a company chooses to install them, NHTSA wants to set official federal standards for the color, brightness, and location. This ensures that any automaker or robotaxi operator using the lights follows a consistent and legal setup rather than creating their own confusing variations.

Major industry players could adopt this standard uniformly. The proposal is relevant to robotaxi operators like Waymo, Nuro, and Zoox, as well as automakers such as GM and Mercedes. By setting a federal baseline, the agency aims to streamline the deployment of these vehicles across the country.

Along with the new light requirements, NHTSA is proposing to remove several lighting rules that do not make sense for driverless vehicles. Current regulations demand physical hazard switches, manual beam shifters, and turn levers inside the cabin. The agency wants to drop these requirements and update the 12.8-volt testing standard. This update would allow automakers to build around modern LED architectures without facing unnecessary administrative hurdles.

The agency is also considering removing requirements that dictate whether high-beam lights must sit above or below low-beam lights. This is part of a broader administrative push by the Department of Transportation to streamline the deployment of autonomous vehicles. The government is trying to make it easier for manufacturers to build cars without traditional controls like steering wheels and pedals, which are designed for human operation.

Regulators are still enforcing existing rules as written, however. Last month, NHTSA opened an audit query into the Tesla Cybercab. The agency is examining the process and technical data Tesla relied on when certifying the vehicle. The central issue is the absence of design features like sideview mirrors, pedals, and a steering wheel, all of which are currently required under FMVSS.